The present invention relates to the improvements in mining apparatus and more particularly to improvements in roof bolting equipment.
Perhaps the single most important consideration and challenge facing miners and mining engineers since the inception of underground mining involves the need to prevent the collapsing of the overhead ceilings or roofs and side walls (xe2x80x9cribsxe2x80x9d) of mines to prevent injury to personnel and catastrophic damage to mining equipment.
Roof bolting and rib bolting are those processes which secure the ribs, side walls and roofs of mines to other stable strata. These processes are relatively slow and are the main causes for preventing mines from advancing at a faster rate.
A currently acceptable method for supporting the roof of a mine entry involves drilling holes at predetermined intervals into the ceiling and ribs and installing elongated retaining bolts in the holes. Such bolts are commonly used in connection with retaining plates and support members. Such apparatus serves to secure together thin strata or bands of rock located adjacent the ribs and roofs and prevent lateral shifting of the strata, as well as, in some instances, to anchor the strata to more massive overlying rock. The installation of retaining bolts into the roof of a mine additionally requires the use of temporary roof support cylinders to support the roof as the bolt holes are being drilled. The reader will appreciate that during the initial engagement between the temporary cylinders and the unsupported section of roof, the condition exists for causing portions of the unsupported roof to fall. Thus, it is desirable for the operation personnel to be as far away from such apparatus as practical during its initial installation.
Over the years, a variety of different types of apparatuses have been developed for installing retaining bolts into the roof and ribs of a mine. An early roof bolting drill is disclosed in U.S. Pat. No. 2,771,273 to Pond. That device comprises an electrical powered drill assembly that is adapted to be manually pulled throughout the mine. Such device offers little protection from roof falls and falling debris during bolt installation.
In an effort to increase the speed of roof bolting, one prior art track mounted roof bolting apparatus was developed, known as the REMB (rapid entry mobile bolter) and was discussed and published in World Mining Equipment April 1997 issue (published by Independent Editorial and Technical Services of the UK). The REMB provides four vertically oriented roof bolting rigs on a forward moveable and raiseable carriage and work platform which is connected to a platform mounted above a track vehicle and which remains stationary relative to the track vehicle. The roof bolting work platform is connected to the stationary platform by a passageway and a series of steps. The bolting carriage and the work platform are attached to the track vehicle by a complex parallel linkage arrangement to the front of the vehicle, so as to keep the rigs at a 90xc2x0 degree angle at all times to the tracks as carriage, work platform and the rigs move up or down. The machine also includes a rib bolt rig behind each operator, which are mounted on the lower stationary platform. The bolting rigs are in a forward position relative to the two operators.
While the REMB has improved the speed of mining, it is not fast enough for many mining applications. One reason for this is the fact that the rib bolters are positioned on the platform which is stationary relative to track vehicle, and this platform is a separate platform from the platform where the operator will control and operate the four roof bolters. This causes several difficulties. The first is that there is a risk of injury for the operators to move up and down steps on platforms, particularly when the steps and the platforms may have water falling thereon making surfaces slippery, even if expanded metal mesh is provided.
The second difficulty relates to the fact that the operators have a bolting down-time as they move from the roof bolting platform to the rib bolting platform.
The REMB also inherently requires the double handling of the consumables as the operator must move a supply of the consumables to the roof bolting platform from the storage area on the REMB, to an area accessible by the operator on the roof bolting platform. This will entail the regular walking up and down of steps to and from the roof bolting platform.
Other prior art roof bolting apparatus mount bolting rigs onto swingable booms. Such equipment however generally form crush points which are hazardous to operators.
A continuous mining machine normally includes a rotatable cutting drum that is mounted on the front end of the mining machine. As the mining machine is advanced into the seam, the cutting drum dislodges or xe2x80x9cwinsxe2x80x9d the coal from the seam. In most continuous mining machines of this type, the won material is conveyed rearwardly of the cutting drum by a longitudinally extending conveyor that may discharge into self-propelled shuttle cars or other mobile conveying apparatuses to transport the won material from the mine face. The mining machine continuously advances into the seam and, as the material is won therefrom, an xe2x80x9centryxe2x80x9d is formed in the underground seam.
While some continuous mining equipment such as that disclosed in U.S. Pat. No. 4,655,507, published and issued on Apr. 7, 1987, have multiple roof bolting rigs mounted thereon, they invariably have a series of roof bolters and rib bolters mounted thereon to provide the full range of roof bolting facilities. However, such equipment can have the same disadvantages as the REMB has due to similar construction features. The continuous miners may have some four operators working to maintain the speed of roof bolting, but the use of two additional operators is a very costly solution to the speed requirements.
Other retaining bolt installation apparatuses are adapted to be affixed to a continuous mining machine for travel therewith. U.S. Pat. No. 3,493,058 to Zitko and U.S. Pat. No. 4,953,914 to LaBegue disclose such devices which can be operated by personnel located on the mining machine. While such apparatus do not require the mining machine to be removed from the entry while bolts are being installed, the mining process is, nonetheless, typically interrupted during the bolting process.
In the cut and flit method of mining, a continuous miner first proceeds down one road, it must then reverse out and turn down a second road and cut that road while a specialised roof bolter bolts in the first mentioned road. The bolter and the continuous miner are continually swapping their roadway positions as the mine face moves forward. The speed of moving forward however is generally limited to the speed of inserting bolts into the ribs and roof of the mine.
The invention in its broadest sense, provides a vehicle which employs hollow structural members to store and cool hydraulic fluid used by the vehicle or by equipment located thereon.
The preferred form of the invention provides an apparatus for installing bolts into a mine entry said apparatus including:
a frame having a forward end, a rearward end and lateral sides, said frame defining a generally horizontal work area;
at least one drive for propelling said frame within said entry;
at least one bolting rig attached to said frame;
a deck member attached to said frame and covering said frame for supporting an operator thereon; and
a return oil tank incorporated into said frame to receive return hydraulic oil from said bolting rig or rigs.
Preferably said frame includes at least one hollow structural member which contains said return oil tank or is said return oil tank.
Preferably said return oil tank forms a significant portion of said frame.
Preferably, said return oil tank has a length greater than its depth and width so that said return oil at any location in said tank is relatively close to the wall forming said tank to assist heat dissipation form said return oil.
Preferably said frame includes at least two hollow structural members which extend along a substantial length of said apparatus and at least two of said hollow structural members are return oil tanks. The front end of a first one of two of said return oil tanks may receive return oil from said at least one bolting rig.
Return oil preferably travels back to a power supply unit by having to traverse the length of said first tank, the length of said second tank and then to said power supply unit. The rear ends of said first and second tanks may have a communicable passage to each other, preferably in the form of a hose connection.
Preferably said apparatus includes a fabricated deck material attached to said frame, said deck enabling water and or slurries which fall onto said deck to fall through and contact the external surfaces of said return oil tank and thus assist to cool down said return oil. A significant proportion of said return oil tank may be located beneath a work area provided on said apparatus for said operators.
If desired the return oil tank can be at least partially incorporated into said deck member to receive return hydraulic oil from said bolting rig or rigs. In this case the return oil tank will have a generally planar upper surface which forms part of the deck member.
Preferably the return oil tank forms a substantial part of the platform, said return oil tank having a substantially greater width and length than depth so that said return oil tank is relatively flat and thin.
Preferably there is included an operator station on said frame for supporting an operator thereon during operation of said at least one roof support member, said operator station located at a position remote from said at least one roof support member, said work area being defined between the at least one bolting rig and the operator station, the return oil tank being at least partially located within the work area.
The return oil tank can have a front wall adjacent the at least one bolting rig and relatively short return oil flow lines join the at least one bolting rig with the return oil tank.
Preferably the apparatus includes at least one drive for propelling said frame within a mine entry, the drive including a pair of spaced apart driven endless tracks on either side of the frame and said return oil tank is dimensioned to fit between said tracks.
The frame can be pivotally connected to the endless tracks by means of a pivot assembly, the pivot assembly being located towards the rearward end of the frame and defining a laterally extending generally horizontal pivot axis. the frame being pivotable about said pivot axis to raise and lower the at least one bolting rig.
The bolting rig is able to rotate about a rotational axis which is aligned with the length of the frame through a range of orientations from approximately 10xc2x0 in an inward direction part vertical, through angles from vertical to horizontal, and 20xc2x0 below horizontal, in an outward direction, so that the included angle in the range is approximately 120xc2x0, the bolting rig being operable in any selected position within that range.
Preferably the apparatus includes two side bolting rigs and central bolting rig aligned in a line which is transverse to the length of the. frame. The side bolting rigs can be mounted on guide frames and are slidable on said guide frames in a lateral direction between extended and retracted positions.
The apparatus can have a removable storage container supported on said frame and at least one roof support member attached to the forward end of said frame adjacent to said at least one bolting rig for selectively supporting said entry as bolts are installed therein in use.
The can be included an operator station on said frame for supporting an operator thereon during operation of said apparatus and said bolting rig, said operator station being located at a position remote and rearward of said at least one bolting rig to define a work area between the operator station and the bolting rig.